-Then i see down Site's and can nod show me page
- how i can resolve this issue?
- how i can limit connection for each ip, for example when each ip have 4 Download with IDM, can not make new download before complete them.
- how i can Limit each Site in My server? when i go to virtual hosts for set this limitation,
set this following value:

I have the most traffic of a site on my server,
when i do limit total to 20KB, problem is solved,
but when do limit same virtual host, i not see any Difference
Please see following screen shot, I've set up properly???

Virtual Host Document Root usually should be $VH_ROOT/public_html. In your case, $VH_ROOT should be "/home/s4music/"; config file should be $VH_ROOT/ms.xml which needs to be readable by admin webserver user 'lsadm'.

For vhost level throttling, set at a lower number such as '4K' to start and see any difference.

BTW, regarding "Running short of concurrent connections", you can try increase Max Connections (Admin Console => Server => Tuning), say from 2000 to 5000, and see any difference.